Chip packaging method

ABSTRACT

A chip packaging method includes followings steps. A plurality of first chips are disposed on a carrier, wherein each of the first chips has a first active surface, and a plurality of first conductive pillars are disposed on the first active surface. A second active surface of a second chip is electrically connected to the first active surfaces of the first chips through a plurality of second conductive pillars. An encapsulated material is formed, wherein the encapsulated material covers the plurality of first chips, the plurality of first conductive pillars, the second chip and the plurality of second conductive pillars. The encapsulated material is partially removed to expose each of the plurality of first conductive pillars. A redistribution structure is formed on the encapsulated material, wherein the redistribution structure connects with the first conductive pillars.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the priority benefit of Taiwan application serial no. 106138744, filed on Nov. 9, 2017. The entirety of the above-mentioned patent application is hereby incorporated by reference herein and made a part of this specification.

BACKGROUND Field of the Disclosure

The invention relates to a chip packaging method.

Description of Related Art

In chip packaging technology, one of the packaging methods is to mount the IC chip on a circuit substrate, and the circuit substrate is electrically connected to the electronic components in the next layer, such as motherboard or module board, etc. According to actual requirements, a plurality of chips are mounted on the same circuit substrate and form a multi-chip package structure, and the chips transmit signals to each other through circuit substrate. However, the line width and the line pitch of the circuit substrate are currently unable to meet the requirements of transmitting signals between multiple chips.

SUMMARY

The invention provides a chip packaging method capable of manufacturing a chip package structure satisfying the requirements of transmitting signal between a plurality of chips.

A chip packaging method of the invention includes followings steps: disposing a plurality of first chips on a carrier, wherein each of the first chips has a first active surface, and a plurality of first conductive pillars are disposed on the first active surface; electrically connecting a second active surface of a second chip to the first active surfaces of the first chips through a plurality of second conductive pillars; forming an encapsulated material, the encapsulated material covering the plurality of first chips, the plurality of first conductive pillars, the second chip and the plurality of second conductive pillars; partially removing the encapsulated material to expose each of the plurality of first conductive pillars; forming a redistribution structure on the encapsulated material, wherein the redistribution structure connects with the first conductive pillars.

Based on the above, in the invention, a chip is electrically connected to at least other two chips in a face to face manner, so as to provide connection paths with greater density and shorter lengths.

In order to make the aforementioned and other features and advantages of the disclosure more comprehensible, embodiments accompanying figures are described in detail belows.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings are included to provide a further understanding of the invention, and are incorporated in and constitute a part of this specification. The drawings illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention.

FIG. 1A to FIG. 1H are cross-sectional schematic views according to a chip packaging method of a one embodiment of the invention.

FIG. 2 is a three-dimensional view of a supporting structure in FIG. 1C including a plurality of openings.

FIG. 3A is a top view of a plurality of first chips and a second chip according to another embodiment of the invention.

FIG. 3B is a top view of a plurality of first chips and a second chip according to another embodiment of the invention.

FIG. 4 is a cross-sectional schematic view according to a chip package structure of another embodiment of the invention.

FIG. 5 is a cross-sectional schematic view according to a chip package structure of another embodiment of the invention.

FIG. 6 is a cross-sectional schematic view according to a chip package structure of another embodiment of the invention.

DESCRIPTION OF THE EMBODIMENTS

Referring to FIG. 1A, in the chip packaging method of the present embodiment, firstly, a plurality of first chips 110 (such as 110-1, 110-2) are disposed on a carrier 102. Each of the first chips 110 has a first active surface 110 a, and a plurality of first conductive pillars 112 are disposed on the first active surface 110 a. To be more specific, the first conductive pillars 112 are respectively disposed on a plurality of pads (not shown) of the first active surface 110 a of the corresponding first chip 110.

Referring to FIG. 1B, a second active surface 120 a of a second chip 120 is electrically connected to the first active surfaces 110 a of the first chips 110 through a plurality of second conductive pillars 122. To be more specific, a plurality of pads (not shown) of the second active surface 120 a of the second chip 120 are electrically connected to a plurality of pads (not shown) of the first active surfaces 110 a of the first chips 110 through the second conductive pillars 122. In the present embodiment, a part of the first active surface 110 a of the first chip 110-1 and a part of the second active surface 120 a of the second chip 120 are opposite each other, and an orthographic projection of the part of the first active surface 110 a of the first chip 110-1 on the carrier 102 overlaps with an orthographic projection of the part of the second active surface 120 a of the second chip 120. In the present embodiment, a part of the first active surface 110 a of the first chip 110-2 and a part of the second active surface 120 a of the second chip 120 are opposite each other, and an orthographic projection area of the part of the first active surface 110 a of the first chip 110-1 on the carrier 102 overlaps with an orthographic projection of the part of the second active surface 120 a of the second chip 120 on the carrier 102. Therefore, the first chip 110-1 and the first chip 110-2 are electrically connected to each other through the second conductive pillars 122 on the first chip 110-1, the second chip 120, the second conductive pillars 122 on the first chip 110-2, so as to provide connection paths with greater density and shorter length. In the present embodiment, a distribution density of the second conductive pillars 122 may be greater than a distribution density of the first conductive pillars 112. Otherwise, an orthographic projection area of the second conductive pillars 122 on the carrier 102 may not be greater than an orthographic projection area of the first conductive pillars 112 on the carrier 102. In addition, a height of the second conductive pillars 122 with respect to the first active surface 110 a is not greater than a height of the first conductive pillars 112 with respect to the first active surface 110 a.

Referring to FIG. 1C, a supporting structure 130 is disposed on the carrier 102 and surrounds the first chips 110. In the present embodiment, the supporting structure 130 has an opening 130 a encircling the first chips 110. The supporting structure 130 assists to improve the structural strength and reduce warpage level.

Referring to FIG. 1D, an encapsulated material 140, such as molding compound, is formed. The encapsulated material 140 partially covers the first chips 110, the first conductive pillars 112, the second chip 120, the second conductive pillars 122, and the supporting structure 130.

Referring to FIG. 1E, the encapsulated material 140 is partially removed to expose each of the first conductive pillars 112. In the present embodiment, the method of partially removing the encapsulated material 140 includes polishing. The encapsulated material 140 is kept to cover the second chip 120.

Referring to FIG. 1F, a redistribution structure 150 is formed on the encapsulated material 140 to redistribute the positions of output signals or input signals. In the present embodiment, the redistribution structure 150 includes a plurality of patterned conductive layers 152, a plurality of dielectric layers 154, and a plurality of conductive vias 156, wherein the dielectric layers 154 and the patterned conductive layers 152 are alternately stacked to one another, and each of the conductive vias 156 is located in the corresponding dielectric layer 154 and electrically connected to the corresponding patterned conductive layers 152. The first chips 110 may be electrically connected to each other not only through the second chip 120 but also through the redistribution structure 150. To be more specific, the first chip 110-1 and the first chip 110-2 are electrically connected to each other through the first conductive pillars 112 on the first chip 110-1, the patterned conductive layers 152 of the redistribution structure 150, and the first conductive pillars 112 on the first chip 110-2. Moreover, the first chip 110-1 and the first chip 110-2 may also be electrically connected to each other through the second conductive pillars 122 on the first chip 110-1, the second chip 120, and the second conductive pillars 122 on the first chip 110-2. In other words, there are at least two types of connection path between the first chip 110-1 and the first chip 110-2, as mentioned above.

Referring to FIG. 1G, after forming the redistribution structure 150, the carrier 102 is removed, so as to expose first backside surfaces 110 b of the first chips 110. At this time, the first backside surface 110 b of the first chips 110, the exposed surface of the encapsulated material 140, and the supporting structure 130 are coplanar with each other.

Referring to FIG. 1H, the redistribution structure 150 has a plurality of redistribution pads 150 a which may be formed by the outermost patterned conductive layer 152. After removing the carrier 102 as shown in FIG. 1G, a conductive contact 160, such as solder ball, is formed on each of the redistribution pads 150 a of the redistribution structure 150 to connect to an electronic component of next level, such as circuit board.

When a plurality of chip package structures 100 are produced in a batch, a plurality of first chips 110 and at least one of second chip 120 form a plurality of chip groups G (FIG. 1B shows only one group in the chip groups G) disposed on the carrier 102. Therefore, referring to FIG. 1G, before forming the conductive contacts 160, a singulation step may be performed, the redistribution structure 150, the encapsulated material 140, and the supporting structure 130 are cut along a cutting line L, so as to separate the chip groups G. At this time, the supporting structure 130 is exposed at a side surface 140 a of the encapsulated material 140. Therefore, each of the chip package structures 100 includes one chip group G, the redistribution structure 150 (such as a part of the redistribution structure 150 after cutting), and the encapsulated material 140 (such as a part of the encapsulated material 140 after cutting).

Similarly, when a plurality of chip package structures 100 are produced in a batch, the supporting structure 130 has a plurality of openings 130 a arranged in array. As shown in FIG. 2, each of the openings 130 a surrounds the corresponding chip group G shown in FIG. 1C. Therefore, as shown in FIG. 1H, each of the chip package structures 100 includes the supporting structure 130 (such as a part of the supporting structure 130 after cutting).

In the present embodiment, a plurality of chip package structures 100, which is arranged in array and is not cut yet, may form a chip package structure array 50, as shown in FIG. 1G. In other words, the chip package structure array 50 includes a plurality of chip package structures 100 arranged in array and not cut yet. To be more specific, each of the chip package structures 100 includes a plurality of first chip 110 (such as 110-1 and 110-2), a plurality of first conductive pillars 112, a second chip 120, a plurality of second conductive pillars 122, an encapsulated material 140 and a redistribution structure 150. Each first chip 110 (such as 110-1 or 110-2) has a first active surface 110 a. Each of the first conductive pillars 112 is disposed on the first active surface 110 a of the corresponding first chip 110. The second chip 120 has a second active surface 120 a. The second active surface 120 a of the second chip 120 is electrically connected to the first active surfaces 110 a of the first chips 110 through the second conductive pillars 122. The encapsulated material 140 partially covers the first chips 110, the first conductive pillars 112, the second chip 120, and the second conductive pillars 122. The redistribution structure 150 is disposed on the encapsulated material 140 and connects with the first conductive pillars 112.

When a supporting structure 130 (shown in FIG. 2) is disposed at the peripheral area of each of the chip package structures 100 of the chip package structure array 50, warpages generated in the process of packaging the chip package structure array 50 may be effectively reduced, so as to improve structural strength of the chip package structure array 50, and to reduce cost in the manufacturing process, in order to increase production yield of the chip package structure 100.

FIG. 4 shows another embodiment of the invention. In comparison with the embodiment shown in FIGS. 1A to 1H, when the carrier 102 is made of heat dissipation material, the chip package structure 100 being completely packaged may keep the carrier 102 in FIG. 1F (such as a part of the carrier 102 after cutting) to serve as a heat dissipation element. At this time, the supporting structure 130 is exposed at a side surface 140 a of the encapsulated material 140 and a side surface 102 a of the carrier 102.

In another embodiment shown in FIG. 5, compared to the embodiment shown in FIG. 1A to 1H, the supporting structure 130 may be omitted so that the chip package structure 100 after being completed does not include the supporting structure 130 in FIG. 1H.

FIG. 6. shows another embodiment of the invention. In comparison with the embodiment shown in FIGS. 1A to 1H, the supporting structure 130 in FIG. 1C may be omitted but the carrier 102 in FIG. 1F may be kept so that the chip package structure 100 after completely packaged does not include the supporting structure 130 but include the carrier 102 in FIG. 1F (such as a part of the carrier 102 after cutting) serving as a heat dissipation element.

The variations of the chip package structure 100 in FIGS. 4 to 6 may be applied to the chip package structure array 50 shown in FIG. 1G. For example, before the chip package structure array 50 being cutting, it may also include the carrier 102 as shown in FIGS. 4 and 6, and the carrier 102 may serve as a heat dissipation element. Moreover, before the chip package structure array 50 being cutting, it may also include the non-cutting supporting structure 130, as shown in FIG. 5.

Referring back to the embodiment in FIG. 1H, the chip package structure 100 includes a plurality of first chip 110 (such as 110-1 and 110-2), a plurality of first conductive pillars 112, a second chip 120, a plurality of second conductive pillars 122, an encapsulated material 140 and a redistribution structure 150. Each of the first chips 110 has a first active surface 110 a, and each of the first conductive pillars 112 is disposed on the first active surface 110 a of the corresponding first chip 110. The second chip 120 has a second active surface 120 a. In the present embodiment, a part of the first active surface 110 a of the first chip 110-1 and a part of the second active surface 120 a of the second chip 120 are opposite each other, and an orthographic projection of the part of the first active surface 110 a of the first chip 110-1 on the first backside surface 110 b of the first chip 110-1 overlaps with an orthographic projection of the part of the second active surface 120 a of the second chip 120 on the first backside surface 110 b of the first chip 110-1. In the present embodiment, a part of the first active surface 110 a of the first chip 110-2 and a part of the second active surface 120 a of the second chip 120 are opposite each other, and an orthographic projection of the part of the first active surface 110 a of the first chip 110-2 on the first backside surface 110 b of the first chip 110-2 overlaps with an orthographic projection of the part of the second active surface 120 a of the second chip 120 on the first backside surface 110 b of the first chip 110-2.

The second active surface 120 a of the second chip 120 is electrically connected to the first active surfaces 110 a of the first chips 110 (such as 110-1 and 110-2) through the second conductive pillars 122. The encapsulated material 140 partially covers the first chips 110, the first conductive pillars 112, the second chip 120, and the second conductive pillars 122. The redistribution structure 150 is disposed on the encapsulated material 140 and connects with the first conductive pillars 112.

In the embodiment of FIG. 1H, the distribution density of the second conductive pillars 122 may be greater than the distribution density of the first conductive pillars 112. Otherwise, an orthographic projection area of the second conductive pillars 122 on the first chips 110 may not be greater than an orthographic projection area of the first conductive pillars 112 on the first chips 110. In addition, the height of the second conductive pillars 122 with respect to the first active surface 110 a is not greater than the height of the first conductive pillars 112 with respect to the first active surface 110 a. A part of the encapsulated material 140 is located between the second chip 120 and the redistribution structure 150 and covers a second backside surface 120 b of the second chip 120. The redistribution structure 150 includes a plurality of patterned conductive layers 152, a plurality of dielectric layers 154, and a plurality of conductive vias 156, the dielectric layers 154 and the patterned conductive layers 152 are alternately stacked to one another, and each of the conductive vias 156 is located in the corresponding dielectric layer 154 and electrically connected to the corresponding patterned conductive layers 152.

In the embodiment of FIG. 1H, the chip package structure 100 further includes a supporting structure 130. The supporting structure 130 surrounds the first chips 110 and is embedded in the encapsulated material 140. The supporting structure 130 is exposed at the side surface 140 a of the encapsulated material 140.

In the embodiment of FIG. 1H, the chip package structure 100 further includes a plurality of conductive contacts 160, such as solder ball. The redistribution structure 150 has a plurality of redistribution pads 150 a, and the conductive contacts 160 are respectively disposed on the redistribution pads 150 a.

It should be noted here, the first chip 110-1 and the first chip 110-2 are electrically connected to each other through the first conductive pillars 112 on the first chip 110-1, the patterned conductive layers 152 of the redistribution structure 150, the first conductive pillars 112 on the first chip 110-2. Moreover, the first chip 110-1 and the first chip 110-2 are also electrically connected to each other through the second conductive pillars 122 on the first chip 110-1, the second chip 120, the second conductive pillars 122 on the first chip 110-2. In other words, there are at least two connection paths between the first chip 110-1 and the first chip 110-2.

Moreover, one second chip 120 is connected to two first chips 110-1 and 110-2 in a face to face manner as described in the embodiments above, but the invention is not limited thereto. In other embodiments, one second chip 120 may also be connected to three first chips (such as 110-1, 110-2 and 110-3 shown in FIG. 3A) or four first chips (such as 110-1, 110-2, 110-3, and 110-4 shown in FIG. 3B), or even more than four first chips 110 depending to requirements in use.

In the embodiment of FIG. 4, in comparison with the embodiment in FIG. 1H, the chip package structure 100 further includes a carrier 102, wherein the material of the carrier 102 is heat dissipation material so that the carrier 102 may serve as a heat dissipation element. The first chips 110, the encapsulated material 140, and the supporting structure 130 are disposed on the carrier 102. The supporting structure 130 is exposed at the side surface 140 a of the encapsulated material 140 and the side surface 102 a of the carrier 102.

In the embodiment of FIG. 5, compared to the embodiment in FIG. 1H, the chip package structure 100 does not include the carrier 130 in FIG. 1H.

In the embodiment of FIG. 6, compared to the embodiment in FIG. 5, the chip package structure 100 further includes a carrier 102. The material of the carrier 102 is heat dissipation material so the carrier 102 may serve as a heat dissipation element. The first chips 110 and the encapsulated material 140 are disposed on the carrier 102.

Summarily, in the invention, a chip is electrically connected to at least other two chips in a face to face manner, so as to provide connection paths with greater density and shorter length. In addition, the supporting structure may be added to assist in improving the structural strength and reducing warpage level. Otherwise, when the material of the carrier is heat dissipation material, the carrier may also be kept to serve as a heat dissipation element.

It will be apparent to those skilled in the art that various modifications and variations can be made to the structure of the disclosed embodiments without departing from the scope or spirit of the disclosure. In view of the foregoing, it is intended that the disclosure cover modifications and variations of this disclosure provided they fall within the scope of the following claims and their equivalents. 

What is claimed is:
 1. A chip packaging method, comprising: disposing a plurality of first chips on a carrier, wherein each of the first chips has a first active surface, and a plurality of first conductive pillars are directly disposed on the first active surface; electrically connecting a second active surface of a second chip to each of the first active surfaces of each of the plurality of first chips directly through a plurality of second conductive pillars; forming an encapsulated material, the encapsulated material covering the first chips, the first conductive pillars, the second chip and the second conductive pillars; disposing a supporting structure on the carrier before forming the encapsulated material, wherein the supporting structure surrounds the first chips, and, after forming the encapsulated material, the encapsulated material covers the supporting structure; partially removing the encapsulated material to expose each of the first conductive pillars; and forming a redistribution structure on the encapsulated material, wherein the redistribution structure connects with the first conductive pillars, wherein a distribution density of the second conductive pillars is greater than a distribution density of the first conductive pillars.
 2. The chip packaging method as recited in claim 1, wherein an orthographic projection area of the second conductive pillars on the first chips is less than or equal to an orthographic projection area of the first conductive pillars on the first chips.
 3. The chip packaging method as recited in claim 1, wherein a height of the second conductive pillars with respect to the first active surface is less than or equal to a height of the first conductive pillars with respect to the first active surface.
 4. The chip packaging method as recited in claim 1, wherein the first chips are electrically connected to each other through the redistribution structure.
 5. The chip packaging method as recited in claim 1, wherein, after partially removing the encapsulated material, the encapsulated material is kept to cover the second chip.
 6. The chip packaging method as recited in claim 1, further comprising: removing the carrier after forming the redistribution structure.
 7. The chip packaging method as recited in claim 1, further comprising: removing the carrier after forming the redistribution structure; and cutting the supporting structure after removing the carrier, wherein the supporting structure is exposed at one side of the encapsulated material.
 8. The chip packaging method as recited in claim 1, further comprising: cutting the supporting structure after removing the carrier, wherein the supporting structure is exposed at one side of the encapsulated material and one side of the carrier.
 9. The chip packaging method as recited in claim 1, further comprising: keeping the carrier to serve as a heat dissipation element after forming the redistribution structure.
 10. The chip packaging method as recited in claim 1, wherein the redistribution structure comprises a plurality of patterned conductive layers, a plurality of dielectric layers, and a plurality of conductive vias, the dielectric layers and the patterned conductive layers are alternately stacked to one another, and each of the conductive vias is located in the corresponding dielectric layer and electrically connected to the corresponding patterned conductive layers.
 11. The chip packaging method as recited in claim 1, further comprising: after forming the redistribution structure, forming a conductive contact on each of a plurality of redistribution pads of the redistribution structure. 